Real Water

So my parents have a play kitchen at their house. It's really the one I made for Wesson for Christmas, but because of the snow it's still at my parents. One of these days I'll get it to my place. Well, back to the play kitchen.... Wesson loves playing with the sink and cups. He pretends to fill up the cups with water. He filled up a cup with water and offered  me a drink. I drank the "water" and then went on talking to my brother. I got thirsty so I told my brother " Hold on, I need to get some water." Wesson hears this and offers me some "water". (I know what a sweet boy.) I told him, "No thank you, Mommy is going to get some real water." Wesson then says, " I want so real water too." and then gets a drink of water. Then for the next 2 hours whenever Wesson wanted water, he would ask for "real water". I wonder how long this "real water" phase will last.